Code division multiple access (CDMA) communication systems provide communication services of wireless radio transmissions. In wireless access networks in accordance with CDMA systems, mobile stations (MSs) connected thereto may be in different states, e.g., active and dormant states. Moreover, a power-on MS may be operating in different states (e.g., active state, control-hold state or dormant state in a cdma2000 system). When an MS is in the dormant state, usually, the wireless access network has no knowledge on the location of the dormant MS. It is ideal in the wireless access network to have knowledge of an MS's location at sector level when the MS is in the dormant state, so as to support fast call setup as well as efficient paging.
Currently, the typical manner in which the network will determine the location of the MS will be to broadcast to the entire network. This presents a significant drain on the network resources. Further, in order for the wireless access network to know an MS's location as it moves through the network, an MS in the dormant state has to report on its location over the reverse link random channel whenever the MS performs an idle handoff. However, such a mechanism to update an MS's location significantly increases the reverse link overhead. It is therefore necessary to reduce the overhead caused by the location update and, at the same time, still enable efficient paging.
In some situations, whenever the network wants to bring the MS in the dormant state back to the active state, the network has to page the MS across the entire network to know the location of the MS. After the MS responds to the paging and the network becomes aware of the location of the MS, the network can allocate dedicated resources to the MS and move it to the active state. Usually, this procedure takes about 1–2 seconds. It has been shown that the system capacity and the MS's end-to-end performance are quite sensitive to the dormant to active state transition delay, especially in a network where packet-data applications dominate the traffic load.
In other situations, the network has data to send to an MS that is in a dormant state, but without bringing the MS back to the active state (e.g., short data burst application). In such instances, the network has to send the data across the whole network as it has no information on the location of the MS. This usually consumes significant forward link resources, especially when the short data burst application is widely supported. If the wireless access network is aware of the location of the MSs in the dormant state, the network will send a short data burst to the MS through the right sector and the consumption of the forward link resource will be reduced. However, due to the consideration of the reverse link overhead, the frequency of sending “location update” messages should be configurable based on different scenarios.
Still other situations address the problem associated with locating the dormant MS through the use of current layer 3 messaging for the purpose of location update. Attached with each such layer 3 message is a list of pilot strengths that is redundant and increases the reverse link overhead.